The Zohar states: "the tav makes an impression on the Ancient of Days." "The Ancient of Days" refers to the sublime pleasure innate within the "crown" (Will) of Divine Emanation. The letter tav (here referring to the "Kingdom of the Infinite One, Blessed be He") leaves its impression on the "Ancient of Days." The impression is the secret of simple faith in God's ultimate omnipresence the Infinite present in the finite, for "there is none like unto Him" (the conclusion of the above quotation from the Zohar).
This faith passes in inheritance from generation to generation, from world to world, the malchut ("kingdom") of the higher world linked to the keter ("crown") of the lower world. The tav, the final letter of the alef-beit, corresponds to malchut ("kingdom"), the final Divine power, in the secret of "Your Kingdom is the Kingdom of all worlds." The impression of the tav is the secret of the power that links worlds - generations - together.
The initial impression of true faith was that which was stamped upon the soul of our first father, Abraham, "the first of all believers." This is the secret of Abraham’s purchase of the Cave of Machpelah, the original Jewish cemetery, for four hundred (the numerical value of tav) shekel, the secret of our eternal inheritance of "four hundred worlds of pleasure," sealed with the stamp of simple faith.
God's seal (in Creation) is truth (in Hebrew, emet, spelled out by the final letters of the three last words in the account of Creation: bara elokim la'asot," " ...God created ‘to do’"). The last letter or seal of the word emet, "truth," itself - the seal of God's seal - is the letter tav, simple faith, the conclusion and culmination of all twenty-two forces - letters - active in Creation.
The three letters which spell emet are the beginning, middle and ending letters of the alef-beit." The alef corresponds to one’s initial awareness of Divine paradox in the infinite source (where the higher and lower waters, joy and bitterness, are absolutely one). From this awareness issues mem, the fountain of Divine wisdom, ever- increasing power of insight into the mysteries of Torah. "The final end of knowledge is not to know." The culmination of the flow of Divine wisdom in the soul (after all is said and done) is the "majestic" revelation of the infinite "treasure-house" of simple faith in God's absolute omnipresence below innate in the soul of Israel. The culmination of truth simple faith is the secret of the "tav."
"All follows the seal," in the secret of "returning light" from the tav to the alef, thereby forming the word ta, "cell." Around the inner Sanctuary of the Temple were constructed many "cells" or "small chambers." These "cells" were without windows, thus being completely dark inside. Chassidut teaches that these "cells" reveal the level of "He places His concealed place in darkness," the awareness of simple faith reaching into the absolutely "dark" Essence of God.
So we are taught: "Torah is the impression [the tav] of Divinity; Israel is the impression [the tav] of Torah." Divinity is perceived first through the service of deepest meditation in complete silence (submission), the secret of the chash ("silence") of chashmal. (Then, through the means of an intermediate stage of "circumcision," comes a first expression of mal, "circumcision." Torah is the secret of separation between good and evil - circumcision - the cutting off of the foreskin (evil).
Israel, the ultimate manifestation of God's Word in Torah ("Israel" is an acronym for the Hebrew phrase "There are six hundred thousand letters in the Torah") corresponds to the final level of "speech," the "second" mal of chashmal. Speech, communication of God's oneness between souls, is the ultimate level of Divine service, "sweetening" all reality, as taught by the Ba'al Shem Tov. The tav, simple faith, is here seen to be the power of impression and linkage uniting the apparently paradoxical extremities of Divine service, from the utter silence of meditation to the loving communication between souls.
A dalet joined to a nun.
A stamp or seal.
Sign; impression; code; in Aramaic: more.